Toner supply containers (e.g. toner bottles, toner cartridges, development units), which contain toner to be supplied to image forming apparatuses, are desired to be reused for environmental protection purposes. However, the process for reusing the toner supply containers results in a considerable cost. The cost mainly consists of the cost for recollecting the toner supply containers and the cost for cleaning the toner supply containers.
The toner, which cannot fulfill various process conditions, is left remaining in the recollected toner supply containers (toner containers). The remaining toner is usually a poor quality toner which coagulates or has a poor charging property, for example. Therefore, in order to ensure the quality of the recycled toner container, it is necessary to remove the remaining toner from the toner container and clean (wash) the inside of the toner container.
Since the toner containers are currently cleaned at a factory having a large-sized facility dedicated for cleaning the toner containers, it is difficult to clean the toner containers at a low cost. Furthermore, since many conventional cleaning processes employ a wet type cleaning method using a cleaning liquid, the conventional cleaning process is complicated. This also results in high cleaning cost. Furthermore, the wet type cleaning method consumes a large amount of energy for disposing the used cleaning liquid and drying the cleaned toner containers. Therefore, the wet type cleaning method is not an ideal method from the aspect of protecting environmental resources.
Japanese Laid-Open Patent Application Nos. 8-173922 and 11-90368 disclose a method of removing residual toner powder remaining (adhering) on the inner and outer surfaces of a powder container containing dry toner for electrophotography, for example. This method employs a cleaning apparatus having an air-blowing part for air-blowing the portion at which the residual toner powder remains and a powder collecting part for collecting the air-blown residual toner powder.
Although this cleaning method may be able to scatter the residual toner powder adhering to the container, the powder collecting part is unable to thoroughly collect the scattered toner powder and leaves toner powder floating inside the container. Furthermore, in a case where the container is made of, for example, resin material, the air-blowing of the toner powder causes friction on the container surface and charges the container surface. The electrostatic force of the charged container surface causes minute scattered toner powder to re-adhere and remain onto the container surface.
In order to improve the efficiency of such a cleaning method, several conventional methods provide multiple oppositely situated opening parts to a development unit or a container. Examples of these conventional methods are shown in Japanese Laid-Open Application Nos. 7-306576 (Toner Container and Cleaning Method), 8-328368 (Development Unit and Cleaning Unit), and 2000-147878 (Recycling Method for Toner Supply Container).
These conventional methods commonly provide a cleaning method in which a high pressure air stream is delivered from one opening part and suctioned out from the other opening part. This cleaning method is a dry type cleaning method which reduces turbulence of the air flow inside the container and generates a powerful toner removing force.
However, the residual stain remaining on the surface of the used toner container not only includes the toner simply adhering onto the surface of the toner container, but also includes the toner coagulated onto the surface of the toner container after extensive use of the toner container. The coagulated toner remaining on the surface of the toner container cannot be easily removed merely by blowing air thereto and the toner container having such coagulated toner cannot be reused. Furthermore, in a case where the toner container is formed in a complex shape, air may not be sufficiently applied to some areas in the toner container. As a result, toner may re-adhere onto such areas and may be difficult to remove.
In order to solve this problem of the residual stain, Japanese Laid-Open Patent Application No. 2002-268383 discloses a cleaning method using a cleaning medium.
In this cleaning method, a granular material, having characteristics of being easy to supply/dispose of, is introduced into a container for allowing residual toner to become attached to the granular material and be removed from the container surface. This granular material is referred to as a cleaning medium. One example of the cleaning medium is a resin ball. FIG. 1 is a schematic drawing for describing a state where residual stain, mainly comprising toner 200, is attached to the surface of a resin ball (cleaning medium) 100. The toner 200 is attached to the resin ball 100 by electrostatic force. By eliminating the electrostatic force of the resin ball 100, the toner 200 can be separated from the resin ball 100. Thereby, the resin ball 100 can be reused as the cleaning medium.
This cleaning method has the following problem in a case of applying this method to a toner supply container.
When the cleaning medium is delivered into one opening part and out from the other opening part of the toner supply container as in the air-blowing method, the cleaning medium is unable to thoroughly reach every corner of the container and may leave uncovered (untouched) areas in the container. In order to allow the cleaning medium to thoroughly cover the internal surface of the container, it is necessary to conduct a batch process (sequential procedures) of introducing the cleaning member into the container, closing the opening parts of the container, and vibrating or shaking the container for a certain period of time. This batch process requires many procedures and lacks operating efficiency.